The Department of Corrections and Rehabilitation says his fellow inmate firefighters tried to revive Anthony Colacino before emergency responders took over Saturday morning. The cause of death is under investigation. No foul play is suspected.

Officials say Colacino collapsed less than an hour into a hike at Sierra Conservation Center prison about 125 miles (200 kilometers) east of San Francisco.

Colacino was sentenced in Riverside County in February 2017 to four years in prison for evading a peace officer, animal cruelty and discharging a firearm with gross negligence.